NASA’s research in 3D terrain visualization can help save lives.
On a December night in 1995, 159 passengers and crew members died when American Airlines Flight 965 flew into the side of a mountain while in route to Cali, Colombia. A key factor in the tragedy: the pilots had lost situational awareness in the dark, unfamiliar terrain. They had no idea the plane was approaching a mountain until the ground proximity warning system sounded an alarm only seconds before impact.

The accident was of the kind most common at the time—CFIT, or controlled flight into terrain.

In situations such as bad weather, fog, or nighttime flights, pilots rely on airspeed, altitude, and other readings to get an accurate sense of location. Miscalculations and rapidly changing conditions can contribute to a fully functioning, in-control airplane flying into the ground.

To improve aviation safety by enhancing pilots’ situational awareness even in poor visibility, NASA began exploring the possibilities of synthetic vision—creating a graphical display of the outside terrain on a screen inside the cockpit.

The World on Display
In 2003, Langley partnered with TerraMetrics Inc. of Littleton, Colorado, through the Small Business Innovation Research (SBIR) program to develop a 3D terrain rendering technology for flight-qualified synthetic vision systems. The company’s innovative solution, called TerraBlocks, rendered satellite imagery on top of terrain data to provide the pilot with a virtual view of the environment outside the cockpit window.

To produce its visuals, TerraBlocks needed satellite imagery and terrain data. For the imagery, the company worked with the Scientific Data Purchase program at Stennis Space Center to locate the data it needed, using an archive from NASA’s Earth-observing Landsat 7 satellite that proved suitable for use in TerraBlocks. NASA’s Shuttle Radar Topography Mission (SRTM) terrain data proved suitable for adding a 3D element.

NASA has used the TerraBlocks engine for multiple experiments with flight simulators for aircraft and even lunar lander vehicles, the latter using a graphical rendering of the Moon the company created. The lander tests demonstrated the potential for synthetic vision on spacecraft.

“If we do manned missions to asteroids or other destinations, all we need is the data and a good navigational system, and we can essentially draw that world for the pilot,” Arthur says.

Envisioning the Future
TerraMetrics now markets its TruEarth satellite imagery and terrain data product line—incorporating the NASA source data from Stennis along with other NASA satellite sources—coupled with its SBIR-developed TerraBlocks terrain-rendering and display engine.

“TruEarth was developed in partnership with NASA,” says Greg Baxes, president of TerraMetrics. “Our goal was to use that data in TerraBlocks, but it also has standalone commercial viability.”

While the TruEarth products have been used extensively in flight simulation and even in movies, television, and animation, most everyday users of the technology encounter it online: The TruEarth 15-meter collection forms the base layer for Google Earth. The imagery is used for views on Google Earth and Google Maps ranging from the global level all the way down to the detail seen when flying about 20,000 feet above the Earth.

“NASA has the charter to look way into the future. Partnering with NASA has allowed us to understand where the future is headed and apply our innovation and technologies in that direction,” he says. “The seed money that we were able to apply to our research and development will pay vast dividends as far as meeting general public and commercial sector needs.”

TerraBlocks™ is a trademark of TerraMetrics Inc.
TruEarth® is a registered trademark of TerraMetrics Inc.

To learn more about this NASA spinoff, read the original article from Spinoff 2011.